.300 Remington Ultra Magnum

History

In 1913 Charles Newton introduced the world’s first high capacity .30 caliber cartridge, based on the 11.2mm Mauser cartridge necked down to .30 caliber. Newton’s cartridge was initially named the .30 Adolph Express after New York rifle builder Fred Adolph but later renamed as the .30 Newton. Case capacity of the .30 Newton was in every way similar to the modern 7mm, .308 Norma and .338 Winchester magnum cartridges however the Newton cartridge did not feature a belted case head. Unfortunately, Charles Newton was plagued with troubles in business. His cartridges never truly saw the light of day and with the introduction of the .300 H&H in 1925, the .30 Newton faded into history.

By the late 1980’s a more informed shooting public was now well aware that a powerful cartridge did not need a belted case. Belted cases may have been handy for wildcat case forming operations and indeed, the belted magnums had proven to be winners at 1000 yards. However the belt no longer served the purpose that it was designed for with the heavily tapered H&H cartridge designs and it’s more recent role as a marketing ploy, the belted case head had run its course.

The 1980’s saw Aubrey White and Noburo Uno of North American Shooting Systems (NASS), based in British Columbia Canada, begin the development of magnum capacity cartridges based on the .404 Jeffery’s Nitro Express. By 1995, basing his designs on the formed brass purchased from Noburo Uno, Don Allen of Dakota Arms had designed a full line of non belted 2.5” case length magnum proprietary cartridges for his Dakota rifles. At the same time, cartridge and rifle designer John Lazzeroni was developing a line of prototype cartridges which later became a line of both long 2.788” magnums and short 2.030” magnums.

In 1999 Remington released the .300 Remington Ultra magnum based loosely on the 404 Jeffery case design. The creation of the .300 Remington Ultra Magnum circumvented the proprietary status from the existing .404 based cartridges while spawning major competition with Winchester. A main feature of both the Remington and Winchester magnums was a rebated rim, allowing these cartridges to work with existing magnum bolt faces. Remington's initial factory loading for the .300 RUM (discontinued) featured the 180gr Nosler Partition at an advertised 3300fps from a 26” barrel. These figures for the 180 grain bullet weight were later revised to 3250fps.

The .300 RUM quickly gained popularity with hunters throughout the western world. A powerful cartridge, producing impressively fast kills on light through to large medium game at close to exceedingly long ranges, this cartridge was for many, an introduction to the idea of long range hunting. Nevertheless, the .300 RUM was not without its idiosyncrasies. Excessive barrel wear, high operating costs, excessive recoil and other contributing factors put the .300 RUM into the same class as high performance race engines. For many hunters, these negative factors have become a major detraction. What was once a love affair with a potent .30 caliber magnum becomes a divorce within 600 rounds. Regardless of this, the .300 RUM is still enjoyed for its strengths by a wide range of hunters with differing needs and will most likely continue to retain a great deal of popularity for decades to come. Of the small bores, the .300 RUM is a true powerhouse.

Performance

The strengths of the .300 RUM can be found in its ability to drive long, heavy .30 caliber projectiles at immensely high velocities. The RUM can launch 180 grain bullets at over 3300fps and 200-210 grain bullets at 3100fps and faster. This power can essentially be utilized in two ways.

On large bodied medium game weighing around 90kg (200lb) and up to 400kg (880lb) and using controlled expanding projectiles, the .300 Rum can be utilized to deliver extremely traumatic wounding within ordinary hunting ranges, effecting the fastest possible, humane kills.

Using long for caliber, fast expanding or frangible projectiles, the .300 RUM can be used as a highly effective long range hunting cartridge for all game up to maximum body weights of around 400kg (880lb).

The ability to produce fast killing on medium to large bodied game weighing between 90kg and 320kg (200-700lb) gives the .300 (and other 300 magnums) an advantage over the 7mm RUM (as well as other 7mm magnums). The science involved is rather straight forwards once it is fully understood but requires careful consideration and study in order to achieve this understanding.

Ahead is a basic example and description of incidents of killing, comparing the 7mm RUM to the .300 RUM with relevant factors in chronological order:

150kg (330lb) deer.
7mm RUM (and magnum family).
Range inside 300 yards.
Conventional soft point (Interlock / Gameking), SST or A-Max of 160-162 grains.
Bullet impacts chest but meets so much resistance that not enough energy is available for the production of hydrostatic shock.
Animal stays standing or runs, time to death around 45 seconds.
Inspection of carcass reveals internal wounding was excellent, vitals destroyed.

Please refer to the game killing section for more detailed information on the exact mechanics of hydrostatic shock, an often misunderstood term.

In the example just given, the .300 RUM produced immensely fast killing in comparison to the sevens. Nevertheless, this does not mean that the same 30 caliber projectiles will give the same results on light bodied deer. Regardless of the power of the .300 RUM, projectiles such as the 180 grain GameKing and Prohunter can produce delayed killing on light framed game by having too much momentum (bullet construction), not meeting enough resistance on impact, resulting in a lack of hydrostatic shock. As always, bullet weights and bullet construction must be matched to the job at hand. Again, referring to the example given, a change to the 160 grain Partition in the 7mm Magnum would have effected immediate collapse of the 150kg animal.

The .300 RUM most definitely has negative aspects. Excessive throat wear is a problem and can occur very quickly. If a rifle is shot in strings for practice, the early signs of accuracy loss can be seen in as little as 300 rounds. With care and attention to barrel heat, friction prevention and bore finish, optimum accuracy can be maintained for approximately 600 rounds. With great care, barrel life can be extended further, for up to 900 rounds. This 600 to 900 round figure is perhaps the most sound barrel budget, but again, bore care and shooting habits are key factors. With cleaning procedures, one could easily reason that the less abrasives used on an already fast wearing abrased bore the better. But the opposite is true, constant polishing prevents the barrel steel at the throat of the RUM’s from becoming porous.

Heated arguments do occur regarding barrel life of the RUM’s. Readers are in this regard asked to consider how such factors as lubricants, polishing methods, barrel steel, barrel contour and shooting strings can effect results. Yet another factor is how shooters define acceptable accuracy. While one shooter may find .75MOA acceptable, another may find this level of accuracy abysmal for long range shooting. When all of these factors are taken into consideration, one can see how easily barrel life results can vary from rifle to rifle and from shooter to shooter.

Remington utilize extremely long free bore to achieve high velocities in the RUM’s. This free bore acts as a gas expansion chamber, allowing for a long peak pressure wave. The .300 RUM uses up to .400” free bore, dictated by the available internal magazine lengths of typical magnum action rifles. In custom rifles, the magazines of the Winchester and Remington rifles can be altered to partially alleviate this potential problem thanks to the Wyatt Outdoors extended magazine box. But in standard form, the shooter can only experiment with ammunition and projectile brands and hope that a given projectile will enter the rifling squarely rather than off center and produce desirable accuracy.

Generally speaking, the longer the projectile, the more it can be guided into the rifling squarely by the RUM case neck. Some rifles do produce desirable accuracy with lighter weight projectiles, experimentation and realistic expectations are the key.

A third negative factor of the .300 RUM is the immense recoil however this can be tamed via muzzle brakes. In unbraked rifles, a weight of 10.5lb field ready is about the minimum for which an experienced shooter can expect consistency of POI at long ranges, requiring sound shooting techniques and sturdy sling tensions as recoil inertia is still evident. Brakes for the .300 RUM should be side ported, rather than spiral ported, the latter having the potential to throw ground debris into the shooters face and across the rifle action unless a ground mat is used.

The velocities of the .300RUM can place extreme demands on projectiles, requiring stout construction for close range impact as well as fast expansion for longer range shots. The higher the impact velocity, the greater the target resistance, resulting in increased stress placed on projectiles. Again, matching bullet weights and bullet construction to game body weights and range is the key to success.

Like all .300 magnums, the .300 RUM is not designed for use on large dangerous game. When used on heavy game, as is reiterated throughout these texts, neck shots followed by head shots (head shots if range and conditions permit) produce the fastest, safest kills.

As with many cartridge designs, the .300 RUM has both its strengths and weaknesses. The trick is being able to understand and work to its strengths, exploiting the full potential of the available power. A high level of personal discipline is required to accurately shoot a stout recoiling magnum along with a sound rifle platform. To be sure, a .300 RUM rifle that groups 1.5” at 100 yards is far less effective in the field than a .308 Winchester that groups .5”.

Factory Ammunition

Remington have recently broken factory loads down into three power levels; 1.fully reduced, 2. partially reduced and 3. full power loads.

Level 1 loads include the 150 grain Accutip (SST) at 2910fps and the traditional 150 grain Core-Lokt also at 2910fps, duplicating the velocities of factory .30-06 ammunition. Level 2 loads include the 180 grain Core-Lokt Ultra at 2980fps and the 180 grain Scirocco at 2980fps, roughly duplicating .300 Winchester Magnum factory ammunition. These downloads beg the question, who would buy a .300 RUM and want to download it? However, as is often the case, reduced loads can produce best accuracy in the light weight SPS style rifles due to the lower recoil inertia. It requires extremely well disciplined technique to shoot full power loads in SPS rifles with great accuracy.

Current full power loads from Remington include the 150gr Swift Scirocco at 3450fps, the 180gr Scirocco at 3250fps, the 180gr Core-Lokt Ultra at 3250fps and the emphatic 200 grain A-Frame at 3030fps.

For open country hunting the 150gr Scirocco is an extremely fast killer, ideal for use on game weighing up to 80kg (180lb) though it can often be relied on to tackle heavier game. Both 180gr loads can be slow killers on light animals. Of the two, the 180 grain Scirocco is the more violent light game bullet. Shot placement is a key factor and on light game, the 180 grain Scirocco can produce spectacular killing when shots strike major shoulder bones.

Remington’s 180 grain loads come into their own on game weighing between 90 and 320kg (200-700lb). That said, at close ranges, if raking shots may have to be taken, neither of these projectiles are able to give deep penetration on Elk sized game due to a tendency to over expand. The 180gr bonded bullets reach their limits on raking shots at velocities of 2800fps, while performance is greatly improved at impact velocities of 2700fps (around 300 yards). Apart from these limitations, the 180 grain core bonded projectiles are extremely effective, especially the Scirocco which often bores an immensely wide wound on large bodied animals.

The 200 grain A-Frame is an excellent large game projectile, ideal for Bear, Elk and Moose out to ordinary hunting ranges. Best performance is derived at impact velocities above 2350fps and the muzzle velocity of 3030fps couldn’t be better in this regard. High trauma and deep penetration are the hallmarks of the A-Frame when it is utilized at optimum velocities and on optimum game weights.

The TBBC is a traumatic, deep penetrating projectile well suited to large bodied game including Grizzly bear. The TSX is also an exceptionally deep penetrating projectile, producing large internal wounds but at times, without the nervous trauma induced by the TBBC (or A-Frame) projectiles, resulting in clean but occasionally delayed kills. Both the TSX and TBBC do their best work at impact velocities above 2600fps, with a further decline in both physical and nervous trauma as impact velocities fall below 2400fps.

Federal’s 200 grain Partition load has great strengths. The Partition works well down to impact velocities of 1800fps and with Federals current loads running true or near true to advertised muzzle velocities, the Partition produces outstanding killing on large bodied medium game out to a range of around 725 yards.

Hand Loading

The .300 RUM can be hand loaded to surpass factory velocities by a considerable margin. Also, unlike the 7mm RUM which struggles to better the velocities of the 7mm STW, 7mm Weatherby and 7mm-.300 Win Mag, the case to bore ratio of the .300 RUM achieves significant increases in velocity over other .300 magnum cartridges.

Large variations in muzzle velocities do occur from rifle to rifle, in some cases this is due to differences in barrel lengths, in other instances, rifle weight is a major factor, the lighter rifles losing accuracy due to severe recoil inertia. Bore tolerances are another factor. With 180 grain projectiles, variations from rifle to rifle, regarding pet accurate loads, can be as wide as from 3200fps to 3400fps. Likewise, 150 grain bullets can sometimes be driven as fast as 3700fps with acceptable accuracy.

As a general rule, light 150 grain bullets are not optimally suited to the .300 RUM free bore design and 1:10 twist rate. Furthermore, the high charges of powder used can generate excessive heat and unnecessary wear. Light projectiles aren’t really necessary in the .300 RUM, now that hunters have access to such explosive designs as the 178 and 208 grain A-Max. However, for hunters who are determined to experiment with light projectiles, the stout 150 grain bullet designs tend to produce more spectacular performance than softer bullet designs which can explode into powdered metal, rather fragmented metal. Light and stout or heavy and soft is the correct mind set for success when selecting loads for the .300 RUM (and most cartridges) for use on light to medium weight deer and antelope species.

Rather than continually reiterating bullet performance at magnum velocities, the section ahead will focus on select bullet designs.

Hornady’s 150 grain SST can suffer the same fate as the 7mm magnum projectiles described in the performance section of the .300 RUM text. Where one might expect immensely spectacular kills on game (light through to medium body weights), at close ranges, the SST can meet too much body resistance due to the high impact velocities. Wounding in such instances can be perfectly adequate but rather than on the spot kills/coma, a lack of hydrostatic shock can allow game to break into a dead run, sometimes covering great distances. The mind boggles as to how prey animals are able to cover considerable distances with such complete wounding. As the 150 grain SST breaks the 3200fps barrier at around 140 yards, it starts to come into its own and at 200 yards, performance on light game is spectacular, retaining the ability to produce excellent killing on light game out to a range of around 930 yards (from 3550fps).

The Hornady InterBond is a good light game projectile for the .300 RUM, reaching its limits (at close ranges) on game weighing around 80kg (180lb). Fast killing is maintained out to 400 yards (2600fps), declining in performance thereafter and especially at around 500 yards (2400fps). As a general purpose projectile for hunting lighter medium game out to 400 yards, the 150 grain InterBond is a sound performer.

Hornady’s 165 grain SST can also meet too much resistance on light to medium weight game when driven at 3400fps. Wounding is exceptional and complete at woods / snap shooting ranges but with the occasional delay in collapse as described. Again, as velocity falls below 3200fps and especially at 3100fps, the 165 grain SST comes into its own. Between 3100 and 2400fps (470 yards), the 165 grain SST is a fast killer of light game. For game weighing between 80 and 150kg (180-330lb), the SST is very fast killing from 3100fps down to 1600fps (130 to 940 yards). Regardless of any occasionally delayed kills, the 165 grain SST is an excellent hunting projectile and the comments here should be taken as a means to further understand and exploit the SST (eg via shot placement) rather than abandoning the SST for its limitations.

The 165 grain SST can also be partnered with the 165 grain InterBond. The InterBond works very well as a 300 yard projectile for use on medium game weighing above 90kg (200lb) and up to around 320kg (700lb).

The 180 grain SST is an exceptional game killer but requires some consideration when used in the .300 RUM. From a muzzle velocity of 3300fps, the 180 grain SST produces fast killing on light framed game with rear lung shots out to 350 yards (2600fps). Beyond this range and more especially as velocity falls below 2400fps, shoulder shots continue to produce fast kills while rear lung shots can result in clean but delayed killing. On game weighing between 80 and 150kg, the 180 grain SST can be a spectacular killer. Penetration is limited at close ranges, the projectile coming to rest against offside skin, making the 180 grain SST more of an open country bullet, working well down to 1600fps. On game weighing between 150 and 320kg (330-700lb), the SST produces deepest penetration at impact velocities below 2600fps (more so below 2400fps), maintaining the balance of excellent wounding versus deep penetration between 350 and 970 yards (2600-1600fps).

The 180 grain SST can be employed for closer range work on Elk sized game so long as the hunter maintains realistic expectations of limitations, using appropriate shot placement. As a long range hunting projectile for use on heavy bodied deer species, regardless of limitations and the mild BC of .480, the SST does have major strengths and should never be overlooked.

The 180 grain InterBond can be used in conjunction with the SST or on its own, ideal for game weighing between 90 and 320kg (200-700lb) out to a range of 350 yards. Performance is not the same as the 200 grain A-Frame and Woodleigh style projectiles when used on very large, very tough game, perhaps due to bullet weight (lower sectional density) more than any other factor.

Hornady’s 178 grain A-Max works exceptionally well on light bodied game. On game weighing between 90 and 150kg (200-330lb), the A-Max does its best work at impact velocities below 3100fps or 90 yards from a MV of 3300fps, producing wide wounding out to ranges of around 1160 yards. But for true long range hunting as well as for general work on medium game at all ranges, the 208 grain A-Max has the greatest strengths. The 208 grain A-Max is perfectly adequate for game as light as 40kg (88lb) upwards. Poor penetration is to be expected on large bodied game at close ranges, especially so at impact velocities above 2900fps. Below 2900fps, penetration is fair. Below 2600fps, the A-Max is able to produce a more uniform cluster of fragments with the potential to produce a deep, central wound channel on large bodied game weighing between 90 and 320kg (200-700lb), with the capacity to tackle somewhat heavier body weights as velocities fall below 2200fps. Driven at 3100fps and with a high BC of .648, the 208 grain A-Max is capable of producing fast kills, with room for error, out to a range of around 1400 yards (1400fps).

One aspect of the 208 grain A-Max (and all of the A-Max family) that needs to be understood, is that below 2600fps, in the absence of hydrostatic shock, mental trauma produced by the A-Max is so severe as to force game into near immediate coma without need of hydrostatic shock transfer. In this instance the brain receives so many messages of damage, that it is forced to shut down for critical control. Game animals bleed out during this period, resulting in what is best described as a painless, humane kill, even though it is pain centers which trigger the shutdown.

At 1400fps, the A-Max family is still able to produce this secondary trauma effect. Where killing is delayed due to errors of wind drift, the potential for shutdown within 10 to 15 seconds is a common occurrence. On top of this, micro fragments of the A-Max can travel at 90 degrees to the wound path, destroying the CNS, including the nerves of the spine and or the autonomous plexus. The A-Max is not however a death ray that can destroy anything it encounters. As always, bullet weights must be matched to game weights and autopsies should be performed with a scientific mindset, the hunter carefully observing the entire wound channel, collecting and recording results.

Speer’s 150 grain Hotcor is a spectacular bullet when driven fast and used on light bodied game. This projectile is stout enough to produce hydrostatic shock at ultra velocities, doing its best work at impact velocities above 2600fps (360 yards) as is common with most small bore soft point projectiles. The Hotcor should not be confused with the 150 grain Speer BTSP which is too soft for use on game in the RUM at close ranges.

The 165 grain Hotcor can be used with great effect on game weighing between 80 and150kg (180-330lb) out to a range of around 360 yards (2600fps), producing clean but delayed killing at 470 yards with wound channels tapering off thereafter. The 165 grain BTSP is a different animal, tackling light through to the afore mentioned 150kg body weights, out to ranges of around 950 yards (1800fps). The BTSP is a highly frangible, immensely soft projectile, ideal for long range applications with its unusually high BC of .520.

The traditional 180 grain Hotcor works very well on large bodied deer, as does its competitor, the 180 grain Sierra Prohunter. Regardless of advances in bullet design, for those on a limited budget wanting a very basic projectile capable of delivering exceptional accuracy and clean killing, this a great bullet. The velocities of the RUM do push the Hotcor to its limits, therefore it is best to avoid using the 180 grain bullet on game weighing over 320kg at close ranges.

Speer’s 180 grain BTSP is an exceptional projectile. With a BC of .545, this bullet renders wide wounding from a MV of 3300fps, out to ranges of around 940 yards (1800fps), steadily tapering in wounding capacity yet still acceptable out at 1100 yards (1600fps) on larger bodied game. Due to its frangible nature, the 180 grain BTSP cannot be expected to produce deep penetration on game weighing around 320kg (700lb) at close ranges. Like the A-Max and SST, on large bodied deer, full cross body penetration and exit wounding is limited at impact velocities above 2600fps, with increased performance at 2400fps (520 yards) and below. The 180 grain BTSP excels on game weighing between 70 and 180kg (155-400lb) at long ranges.

Without a doubt, the 200 grain Speer Hotcor is a great performer, delivering high trauma. Weight loss tends to average 50% much like the Accubond, allowing for deep penetration on large bodied deer weighing between 90 and 320kg (200-700lb).

Nosler’s 150 grain Accubond can be an excellent performer on light game in open country. Wounding tends to be more violent than Hornady’s 150 grain InterBond and blow back entry wounds of a large diameter can occur from time to time. As with other core bonded designs, best results are obtained at impact velocities above 2600fps. The 150 grain Partition is another violent performer but continues to produce wide wounding down to 1800fps.

The 180 grain Accubond can struggle at times to maintain full integrity when driven at RUM velocities and used at close ranges on large bodied game. In the RUM the 180 grain Accubond does its best work on game weighing between 90 and 150kg (200-330lb). A better projectile for the .300 RUM, is Nosler’s 200 grain Accubond. However, readers must be aware, this projectile does lose a lot of weight during penetration and is not as tough as the likes of the 200 grain Woodleigh or A-Frame designs. Instead the 200 grain Accubond works well on large bodied deer out to ordinary hunting ranges, producing excellent wounding and fast killing when utilized accordingly.

One projectile that deserves consideration for use in the .300 RUM, is the Nosler 180 grain Ballistic Tip. Typically this projectile can be a little too stout for light game and sometimes too frangible for heavy bodied medium game, but in the RUM, the BT has merit. For hunters who find the A-Max projectiles to be too frangible for use on large bodied game at long ranges, the BT is stouter. This is still a frangible projectile and expansion is reliable, without risk of pin hole wounding at low velocities. BC of the 180 grain BT is .507, not the highest for long range work however, BC should not always be put ahead of all other factors when choosing long range hunting projectiles. The BT tends to show a gradual reduction in wound channel diameters as velocities fall below 2400fps, however, body resistance alters performance. The greater the body resistance, the greater the level of expansion and fragmentation and under optimal conditions, full expansion, fragmentation and optimal wounding can occur with the BT at velocities as low as 1400fps.

Nosler’s 180 grain Partition produces excellent performance on large bodied deer but in the .300 RUM, is bested by the 200 grain Partition. Fast expansion down to 1800fps and violent wounding are hallmarks of the Partition and in rifles that won’t shoot this bullet accurately, the rifle should be brought to question as Partition projectiles can produce outstanding accuracy. The 200 grain Partition can be used reliably on game weighing between 90 and 400kg (200-880lb).

Swift’s 150 grain Scirocco has a longer bearing surface than other 150 grain projectiles due to its very thick jacket, much like Barnes bullets. This gives the Scirocco an advantage when utilized in the 1:10 twist / long free bore design of the RUM. The Scirocco is perhaps the best of the 150 grain bullets for use on light bodied game in the .300 RUM down to impact velocities of 2400fps.

Swift’s 180 grain Sirocco is a violent performer on game weighing between 90 and 150kg (200-330lb). On heavier game weighing around 320kg (700lb), at close ranges, wounding is violent but penetration is not outstanding, showing much better penetration as velocities fall below 2900fps. Between 2900fps and 2600fps, the Scirocco shows great strengths when used on Elk sized game. Below 2600fps, wounding is still complete, however, clean but delayed killing can be expected with rear lung shots as is the nature of core bonded bullet designs. To fully exploit the potential of the Scirocco in open country on large bodied game, shot placement is the key. With well placed shoulder shots, from an MV of 3300fps, fast and very emphatic kills can be obtained at impact velocities as low as 2200fps (600 yards).

In the .300 RUM, the 200 grain A-Frame is an alpha predator. For tough, mean spirited game, this projectile delivers both intense trauma and deep penetration. Trauma is twofold involving both hydrostatic shock above 2600fps as well as mental trauma, sending game into coma followed by death. This trauma continues down below 2600fps, often resulting in instant collapse at impact velocities of 2400fps (340 yards).

Along with the A-Frame, one of my favorite final solutions, is the 200 grain Woodleigh Magnum. The .300 RUM (and .30-378) are hard on both the A-Fame and Woodleigh projectiles, eventually ruining SD in both bullet designs during penetration. But dead is dead and these projectiles are not just tough but also offer fast expansion for immediate and continued energy transfer.

Woodleigh also offer several other bullet designs in .30 caliber. The softer, lower velocity projectiles should not be overlooked for certain applications as even the softest Woodleigh does not fall to pieces on impact. As has been reiterated through the various texts of the .30 calibers, Woodleigh allow a lot of room for experimentation and exact tailoring. One example, is the 240 grain Woodleigh PP. This is designed for impact velocities of 2400fps to 1900fps. Driven at 2700-2800fps, the 240 grain Woodleigh breaks the 2400fps barrier at 130-180 yards. But even when it is driven beyond its design parameters at high impact velocities, the Woodleigh never fails to penetrate deeply, rendering wide wounds on tough, heavy game.

Barnes produce the meat saver bullets of the .300 RUM world. The 150 grain Barnes, which produces fast killing at impact velocities above 2600fps is well suited to light through to medium weight game weighing up to 150kg. Any petal loss at close ranges should not be seen as a concern as this does not affect wounding or penetration on game of these weights. Internal wounding produced by the 150 grain Barnes is very wide but as always, meat damage tends to be lower in comparison to other bullet styles, unless major bones are encountered on impact.

The Barnes 165 and 168 grain TSX bullets can produce slow kills on game weighing under 90kg (200lb). As body weight and resistance increases above the 90kg mark, these projectiles come into their own, excelling on game weighing between 200-320kg (440-700lb). Of all of the projectile brands and designs, the Barnes TSX is least effected by increases in muzzle velocity, from the .30-06 through to the .300 RUM and .30-378. Nevertheless, the longer the TSX can be kept above 2600fps, the more it is able to produce fast killing on large bodied game. The 180 and 200 grain Barnes 30 TSX bullets again, require body weights of over 90kg (200lb), being well suited to game weighing between 200 and 400kg (440-880lb) at impact velocities of above 2400fps. On heavy game weighing around 600kg (1300lb), although the TSX has no trouble producing an exit wound, delayed killing can occur as a result of narrow wounding, proportionate to game body weights. In essence, wider bores produce wider wounds.

The .300 RUM does not have enough velocity to make uniform the erratic results that can occur with the current Berger bullet design if bullet weights are not matched to game weights. In the .300 RUM, the 175 to 190 grain Berger VLD bullets can be annealed (blowtorched in a shallow pan of water to prevent lead erupting) and made useful for work on game weighing between 90 and 180kg (200-400lb). The 210 grain VLD is a useful bullet for Elk sized game at long ranges but again, it should be annealed at the Ogive to promote expansion followed by fragmentation. Annealed with a full color change at the ogive to brown/blue, the VLD can be made to produce desirable wounding down to an impact velocity of 1400fps.

Time will tell with the VLD, hopefully we will see more changes and further enhancements in the future.

Closing Comments

The .300 RUM is an immensely potent cartridge. However, in order to harness this power, the rifle must be accurate and the bullet matched to the job at hand. For those seeking the hammer of Thor, able to kill all game emphatically with a single load, this is not the cartridge, nor is any other. The .300 RUM deserves careful consideration. Intended game body weights and ranges are primary considerations. Accuracy, realistic expectations, budget and clear goals are also keys to success with this cartridge. For the hunter who wishes to take large bodied medium game at 700-1000 yards, this job can be done very easily, emphatically and dramatically with the .300 Winchester Magnum. As a long range hunting cartridge, the .300 RUM in the hands of an experienced shooter, comes into its own at the extreme ranges of 1200 to 1400 yards. That the .300 RUM is a powerful cartridge there is no doubt. The challenge is understanding how to utilize this power productively.

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ABOUT US

We are a small, family run business, based out of Taranaki, New Zealand, who specialize in cartridge research and testing, and rifle accurizing.